Either we have an eight-sided love "triangle" (ie, 1 loves 2 who loves 3 who loves 4 who loves 5 who loves 6 who loves 7 who loves 8 who loves 1) or we have two 4-sided "triangles" (1 loves 2 who loves 3 who loves 4 who loves 1).

Clues 4 and 6 mean that Gloria and Rose and Mary are in the same triangle, so that it must be the first case. In fact, from clues 4 and 6, Gloria loves ? loves Rose loves ? loves Mary loves ? loves Jill loves ? loves Gloria.